The High Court is hearing a case where a public servant wants workers compensation after being injured while having sex during a work trip in 2007.

The incident happened when the public servant travelled to a New South Wales country town as part of her job.

She suffered injuries to her face after a light fitting came off the wall while she was having sex in her room.

Initially Comcare agreed to compensation but then revoked the claim.

The Federal Court later ruled in favour of the woman, prompting the High Court challenge.

The Commonwealth has told the High Court the incident was after hours and not in the course of her employment, so she should not be entitled to compensation.

But lawyers for the woman say the days of the 'master and servant relationship' are over, and it is not reasonable for her employer to dictate her after hours activities so long as there is no wilful misconduct.

The court heard since the incident happened in the room booked by the employer it is liable for compensation.